Filter



FIG. 1 is a top view of a filter, showing my new design;

FIG. 2 is a bottom view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof

FIG. 5 is a left side thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is an exploded view thereof.

The dashed lines in the drawing views depict portions of the design that form no part of the claim. 

CLAIM The ornamental design for a filter, as shown and described. 